LED lighting manufacturer Bridgelux recently announced that they were able to successfully use silicon wafers to make commercial grade LED components. This is the first time this has been done, and it has serious implications for the lighting industry in that it shows that inexpensive LED light bulbs
are much closer to being a reality than previously thought.
Most current LEDs are manufactured on substrates
of costly materials such as sapphire or silicon carbide. This is one of the biggest reasons LED light bulbs are so expensive, and one of the reasons why lighting manufacturers are constantly looking for manufacturing alternatives. Some companies put their efforts into trying to obtain larger amounts of sapphire or silicon carbide at once to drive down the price they can offer per unit, but Bridgelux has moved their research to silicon, the core material of computer chips.
Silicon is far cheaper than sapphire and other costly materials, but it has the added benefit of being able to utilize existing semiconductor factories. These two reasons are why silicon could contribute to far less expensive LED light bulbs. Most previous attempts at using silicon for LED applications failed because the performance of LEDs made with silicon fell far short of LEDs made with conventional materials.
Bridgelux announced that it had managed to use eight-inch silicon wafers to make LEDs which produced 135 lumens per watt. If this can be replicated at a commercial scale, then we're looking at a future where solid state lighting technology could be affordable for the masses. Bill Watkins, CEO of Bridgelux said he saw no barriers to using the approach to reduce production costs by 75% and spoke of a time when LED light bulbs could be available for as little as $5.
The company anticipates commercial production of inexpensive LED light bulbs in as little as two to three years. That seems unlikely to me, but I'd certainly love to see it!